1. Field of the Invention
This invention relates to an apparatus for detecting the intensity and/or the density of shot blasting used for shot treatment, and more particularly to an apparatus which can detect the intensity of shot blasting while a work is being subjected to shot treatment.
2. Description of the Related Art
In shot treatment, such as, so-called shot blasting or shot peening, a shot stream of beads of a hard material, such as, steel, aluminium, zinc, glass or ceramics, having a diameter of about 0.2 to 2.0 mm is projected toward and onto the surface of a steel work so as to remove scale or burr from the surface of the steel or aluminium work or so as to harden the surface of the steel or aluminium work. Hitherto, the average intensity or the density of such a shot stream is measured for detecting the intensity of the shot blasting or shot peening, as described in, for exmaple, "Shot Peening Ductile Iron", Modern Casting/February 1990, pp. 51-53. That is, utilizing the fact that, when a steel strip is subjected to projection of a shot stream, the steel strip tends to deflect or bend upward toward the side that has received the shot, this arc height in deflection is measured by a gauge so as to detect the average intensity of the shot stream. Also, the dimpling formed on the surface of the steel strip by projection of the shot stream is photographed, and the rate or coverage of the dimpling is then measured so as to detect the density of the shot stream. However, in these methods for detecting the degree of shot blasting or shot peening, the steel strip is subjected to the measurement by taking out the steel strip from a shot blasting machine after completion of the shot blasting treatment. Thus, although these methods are preferable for determining beforehand the conditions of shot blasting, it is difficult to utilize these methods for carrying out shot blasting under optimum conditions while monitoring the actual intensity and/or density of the shock stream.